Identification and characterisation of hypomethylated DNA loci controlling quantitative resistance in Arabidopsis

First author: Leonardo Furci; Affiliations: University of Sheffield (谢菲尔德大学): Sheffield, UK

Corresponding author: Jurriaan Ton

Variation in DNA methylation enables plants to inherit traits independently of changes to DNA sequence. Here, we have screened an Arabidopsis population of epigenetic recombinant inbred lines (epiRILs) for resistance against Hyaloperonospora arabidopsidis (Hpa). These lines share the same genetic background, but show variation in heritable patterns of DNA methylation. We identified 4 epigenetic quantitative trait loci (epiQTLs) that provide quantitative resistance without reducing plant growth or resistance to other (a)biotic stresses. Phenotypic characterisation and RNA-sequencing analysis revealed that Hpa-resistant epiRILs are primed to activate defence responses at the relatively early stages of infection. Collectively, our results show that hypomethylation at selected pericentromeric regions is sufficient to provide quantitative disease resistance, which is associated with genome-wide priming of defence-related genes. Based on comparisons of global gene expression and DNA methylation between the wild-type and resistant epiRILs, we discuss mechanisms by which the pericentromeric epiQTLs could regulate the defence-related transcriptome.

DNA甲基化的变异使得植物能够在不依赖于DNA序列改变的情况下进行性状遗传。本文，作者对拟南芥表观重组自交系群体epiRIL进行了活体营养型卵菌Hpa的抗性鉴定。这些株系具有相同的遗传背景，但DNA甲基化的遗传模式不同。作者鉴定了4个表观数量性状位点epiQTL，这些位点能够在不减缓植株生长和降低对其它生物或非生物胁迫胁迫的情况下提升植株的数量抗病性。表型鉴定及RNA-seq分析揭示了Hpa抗性epiRIL群体植株能够在病菌侵染较早时期就启动防御响应。综上，本文的研究显示低甲基化的近着丝粒区域能够为植株提供数量抗病性，而这与基因组范围上某些防御相关基因的预先响应有关。基于野生型和抗性epiRIL植株的基因表达和DNA甲基化的比较分析，作者进一步讨论了近着丝粒epiQTL能够调控全基因组范围上抗性相关基因转录的机制。

通讯：Jurriaan Ton (https://www.sheffield.ac.uk/aps/staff-and-students/acadstaff/ton)

个人简介：1996年，荷兰乌得勒支大学，生物学硕士；2001年，荷兰乌得勒支大学，生物学博士；2001年，荷兰乌得勒支大学，博士后；2001-2004年，瑞士纽奇大学，博士后。

研究方向：植物如何通过自身免疫系统适应环境胁迫。

doi: 10.7554/eLife.40655

Journal: eLife

Published date: 04 January, 2019